Mystery inhabitant ?

[Groucho]

Lately I've noticed a lot of tiny chips at the base of some of my live rock. There is no damage to the outside of the rock, so I'm assuming that some kind of critter has taken up residence and is doing a little remodeling inside the live rock.

Does anybody have a similar experience? Any ideas what it might be?

Thanks

[JennM]

Could be a crab or a mantis...or a rock-boring worm...hard to say but interesting...

Jenn

[Spanky]

Groucho,

There's all kinds of critters that could be in your live rock. Most would not be actually eating the rock but excavating a already existing tunnel/space and pushing the sand grains out. Also, if this looks like a little pile of clean sand right up against the base of the rocks, you could have lug worms in your sand that are actually building little sand volcanoes as they make their tunnels in the sand.

Look at this picture of our tank, bottom far left, up against the rock. That's a lug worm volcano.

http://rockyshores.saltyzoo.com/rock...h/crop0034.jpg

Spanks

[Groucho]

Thanks for the replies.

[CAT]

I've got about 8 little 'mountains' in my substrate. Looks like a filter feeder in there. What I see is a tube with one or two strings coming out of the tube.

Very annoying - I smooth out the substrate when cleaning the tank and the mountains are there again the next day. They're winning the turf war, I think

[greenbud]

Originally posted by CAT
I've got about 8 little 'mountains' in my substrate. Looks like a filter feeder in there. What I see is a tube with one or two strings coming out of the tube.

From the FAQ: polychaete of the Family Spionidae. They are harmless detritivores that use their tentacles to pull in detritus and other organic particles. In addition to detritus, they are also quite capable of snaring small pieces of fish food drifting in the water column. They are very similar to Terebellid worms

Groucho.. may be helpful if you ever get a good look: http://www.reefs.org/hhfaq/pages/mai...s/faq_sand.htm